About 230 million surgeries take place annually world-wide; 40 million US patients undergo in-hospital general anesthesia, which induces loss of consciousness, each year, and 25 million of those also receive muscle relaxants (also called neuromuscular blocking agents, NMBAs), which inhibit neuromuscular transmission. These relaxant agents decrease muscle tension and suppress reflex contractions.
Muscle relaxants (NMBAs) have two forms: depolarizing agents, which are short-acting (5-10 min duration) and are sometimes used at the start of anesthesia to facilitate tracheal intubation, and non-depolarizing agents that have a longer duration of action (20-60 min), and that are used to maintain muscle relaxation during surgery. The effects of non-depolarizing agents start within minutes and continue for up to 20-60 minutes after withdrawal (depending on the type of relaxant used), so they must be administered repeatedly throughout the surgical procedure.
Systems and methods for monitoring neuromuscular function have been proposed. For example, systems and methods for assessing the level of neuromuscular blockade in a subject having been administered NMBAs have been proposed. The systems and methods for monitoring neuromuscular function can include electrode systems for delivering electrical stimulation to a motor nerve of the subject and recording for a corresponding nerve and/or muscle response to the electrical stimulation, for example.